You just described me perfectly, OPIt may not be a big deal for you, but someone with 20-50 dives all in warm water always with a guide, it can be a big deal.

Personally, I am not offended in the slightest by your earlier post either (although I can see how some perhaps would be at the idea that their initial cert wasn't "enough"). I recognize that I am in no way "competent" right now to go diving in the Pacific NW, or NorCal, or many other places without further instruction/guidance. Cold water diving is a different ballgame. And as I think I posted earlier here, I knew that the training we received was really for the environment where we got it, and that if we ever had notions of doing "real" dives we would need more guidance or else potentially find ourselves in serious trouble. Full credit to our instructor for making that clear, and I do not at all feel like we were short-changed on the instruction we received. Possibly I'm just a sucker

No question, in my mind, those who get their certifications in more challenging environments are far more "competent" than I am. In my case retaking OW in its entirety might be extreme, but perhaps paying for some time with a local instructor, with instruction tailored for the environment (with the instructor knowing what my current experience is) would be appropriate. I certainly wouldn't expect an instructor to bring me to a different level of competence for free. I don't know how many fairly newly minted tropically trained divers have the same mindset that I do about being "out of their depth" or "over their head", so to speak (pun not intended but certainly seems appropriate in this context...)
But it's not just temperature. Coz is the same warm water tropical environment (heck it's the same Mezoamerianc reef!) where I have acquired all of my (limited) experience, but I have never dealt with the kind of currents that I read described on some dives there. Never used a reef hook, for example, and while I understand the "theory" of "ducking around a coral head", in practice I would want some additional training before I did a dive like that. Because to me, at my current level of experience, that would be concering too.